#ifndef __ARES_PRIVATE_H
#define __ARES_PRIVATE_H

/* Copyright 1998 by the Massachusetts Institute of Technology.
 * Copyright (C) 2004-2010 by Daniel Stenberg
 *
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in
 * advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 */

 /*
  * Define WIN32 when build target is Win32 API
  */

#if (defined(_WIN32) || defined(__WIN32__)) && !defined(WIN32)
#define WIN32
#endif

#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#ifdef WATT32
#include <tcp.h>
#include <sys/ioctl.h>
#define writev(s,v,c)     writev_s(s,v,c)
#define HAVE_WRITEV 1
#endif

#define DEFAULT_TIMEOUT         5000 /* milliseconds */
#define DEFAULT_TRIES           4
#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif

#ifdef CARES_EXPOSE_STATICS
  /* Make some internal functions visible for testing */
#define STATIC_TESTABLE
#else
#define STATIC_TESTABLE static
#endif

#if defined(WIN32) && !defined(WATT32)

#define WIN_NS_9X      L"System\\CurrentControlSet\\Services\\VxD\\MSTCP"
#define WIN_NS_NT_KEY  L"System\\CurrentControlSet\\Services\\Tcpip\\Parameters"
#define NAMESERVER     "NameServer"
#define DHCPNAMESERVER "DhcpNameServer"
#define DATABASEPATH   L"DatabasePath"
#define WIN_PATH_HOSTS L"\\hosts"

#elif defined(WATT32)

#define PATH_RESOLV_CONF "/dev/ENV/etc/resolv.conf"

#elif defined(NETWARE)

#define PATH_RESOLV_CONF "sys:/etc/resolv.cfg"
#define PATH_HOSTS              "sys:/etc/hosts"

#elif defined(__riscos__)

#define PATH_HOSTS             "InetDBase:Hosts"

#else

#define PATH_RESOLV_CONF        "/etc/resolv.conf"
#ifdef ETC_INET
#define PATH_HOSTS              "/etc/inet/hosts"
#else
#define PATH_HOSTS              "/etc/hosts"
#endif

#endif

#define ARES_ID_KEY_LEN 31

#include "ares_ipv6.h"
#include "ares_llist.h"

#ifndef HAVE_GETENV
#  include "ares_getenv.h"
#  define getenv(ptr) ares_getenv(ptr)
#endif

#include "ares_strdup.h"

#ifndef HAVE_STRCASECMP
#  include "ares_strcasecmp.h"
#  define strcasecmp(p1,p2) ares_strcasecmp(p1,p2)
#endif

#ifndef HAVE_STRNCASECMP
#  include "ares_strcasecmp.h"
#  define strncasecmp(p1,p2,n) ares_strncasecmp(p1,p2,n)
#endif

#ifndef HAVE_WRITEV
#  include "ares_writev.h"
#  define writev(s,ptr,cnt) ares_writev(s,ptr,cnt)
#endif

  /********* EDNS defines section ******/
#define EDNSPACKETSZ   1280  /* Reasonable UDP payload size, as suggested
								in RFC2671 */
#define MAXENDSSZ      4096  /* Maximum (local) limit for edns packet size */
#define EDNSFIXEDSZ    11    /* Size of EDNS header */
								/********* EDNS defines section ******/

struct ares_addr {
	int family;
	union {
		struct in_addr       addr4;
		struct ares_in6_addr addr6;
	} addr;
	int udp_port;  /* stored in network order */
	int tcp_port;  /* stored in network order */
};
#define addrV4 addr.addr4
#define addrV6 addr.addr6

struct query;

struct send_request {
	/* Remaining data to send */
	const unsigned char *data;
	size_t len;

	/* The query for which we're sending this data */
	struct query* owner_query;
	/* The buffer we're using, if we have our own copy of the packet */
	unsigned char *data_storage;

	/* Next request in queue */
	struct send_request *next;
};

struct server_state {
	struct ares_addr addr;
	ares_socket_t udp_socket;
	ares_socket_t tcp_socket;

	/* Mini-buffer for reading the length word */
	unsigned char tcp_lenbuf[2];
	int tcp_lenbuf_pos;
	int tcp_length;

	/* Buffer for reading actual TCP data */
	unsigned char *tcp_buffer;
	int tcp_buffer_pos;

	/* TCP output queue */
	struct send_request *qhead;
	struct send_request *qtail;

	/* Which incarnation of this connection is this? We don't want to
	 * retransmit requests into the very same socket, but if the server
	 * closes on us and we re-open the connection, then we do want to
	 * re-send. */
	int tcp_connection_generation;

	/* Circular, doubly-linked list of outstanding queries to this server */
	struct list_node queries_to_server;

	/* Link back to owning channel */
	ares_channel channel;

	/* Is this server broken? We mark connections as broken when a
	 * request that is queued for sending times out.
	 */
	int is_broken;
};

/* State to represent a DNS query */
struct query {
	/* Query ID from qbuf, for faster lookup, and current timeout */
	unsigned short qid;
	struct timeval timeout;

	/*
	 * Links for the doubly-linked lists in which we insert a query.
	 * These circular, doubly-linked lists that are hash-bucketed based
	 * the attributes we care about, help making most important
	 * operations O(1).
	 */
	struct list_node queries_by_qid;    /* hopefully in same cache line as qid */
	struct list_node queries_by_timeout;
	struct list_node queries_to_server;
	struct list_node all_queries;

	/* Query buf with length at beginning, for TCP transmission */
	unsigned char *tcpbuf;
	int tcplen;

	/* Arguments passed to ares_send() (qbuf points into tcpbuf) */
	const unsigned char *qbuf;
	int qlen;
	ares_callback callback;
	void *arg;

	/* Query status */
	int try_count; /* Number of times we tried this query already. */
	int server; /* Server this query has last been sent to. */
	struct query_server_info *server_info;   /* per-server state */
	int using_tcp;
	int error_status;
	int timeouts; /* number of timeouts we saw for this request */
};

/* Per-server state for a query */
struct query_server_info {
	int skip_server;  /* should we skip server, due to errors, etc? */
	int tcp_connection_generation;  /* into which TCP connection did we send? */
};

/* An IP address pattern; matches an IP address X if X & mask == addr */
#define PATTERN_MASK 0x1
#define PATTERN_CIDR 0x2

struct apattern {
	union
	{
		struct in_addr       addr4;
		struct ares_in6_addr addr6;
	} addr;
	union
	{
		struct in_addr       addr4;
		struct ares_in6_addr addr6;
		unsigned short       bits;
	} mask;
	int family;
	unsigned short type;
};

typedef struct rc4_key
{
	unsigned char state[256];
	unsigned char x;
	unsigned char y;
} rc4_key;

struct ares_channeldata {
	/* Configuration data */
	int flags;
	int timeout; /* in milliseconds */
	int tries;
	int ndots;
	int rotate; /* if true, all servers specified are used */
	int udp_port; /* stored in network order */
	int tcp_port; /* stored in network order */
	int socket_send_buffer_size;
	int socket_receive_buffer_size;
	char **domains;
	int ndomains;
	struct apattern *sortlist;
	int nsort;
	char *lookups;
	int ednspsz;

	/* For binding to local devices and/or IP addresses.  Leave
	 * them null/zero for no binding.
	 */
	char local_dev_name[32];
	unsigned int local_ip4;
	unsigned char local_ip6[16];

	int optmask; /* the option bitfield passed in at init time */

	/* Server addresses and communications state */
	struct server_state *servers;
	int nservers;

	/* ID to use for next query */
	unsigned short next_id;
	/* key to use when generating new ids */
	rc4_key id_key;

	/* Generation number to use for the next TCP socket open/close */
	int tcp_connection_generation;

	/* The time at which we last called process_timeouts(). Uses integer seconds
	   just to draw the line somewhere. */
	time_t last_timeout_processed;

	/* Last server we sent a query to. */
	int last_server;

	/* Circular, doubly-linked list of queries, bucketed various ways.... */
	/* All active queries in a single list: */
	struct list_node all_queries;
	/* Queries bucketed by qid, for quickly dispatching DNS responses: */
#define ARES_QID_TABLE_SIZE 2048
	struct list_node queries_by_qid[ARES_QID_TABLE_SIZE];
	/* Queries bucketed by timeout, for quickly handling timeouts: */
#define ARES_TIMEOUT_TABLE_SIZE 1024
	struct list_node queries_by_timeout[ARES_TIMEOUT_TABLE_SIZE];

	ares_sock_state_cb sock_state_cb;
	void *sock_state_cb_data;

	ares_sock_create_callback sock_create_cb;
	void *sock_create_cb_data;

	ares_sock_config_callback sock_config_cb;
	void *sock_config_cb_data;
};

/* Memory management functions */
extern void *(*ares_malloc)(size_t size);
extern void *(*ares_realloc)(void *ptr, size_t size);
extern void(*ares_free)(void *ptr);

/* return true if now is exactly check time or later */
int ares__timedout(struct timeval *now,
	struct timeval *check);

void ares__send_query(ares_channel channel, struct query *query,
	struct timeval *now);
void ares__close_sockets(ares_channel channel, struct server_state *server);
int ares__get_hostent(FILE *fp, int family, struct hostent **host);
int ares__read_line(FILE *fp, char **buf, size_t *bufsize);
void ares__free_query(struct query *query);
unsigned short ares__generate_new_id(rc4_key* key);
struct timeval ares__tvnow(void);
int ares__expand_name_for_response(const unsigned char *encoded,
	const unsigned char *abuf, int alen,
	char **s, long *enclen);
void ares__init_servers_state(ares_channel channel);
void ares__destroy_servers_state(ares_channel channel);
#if 0 /* Not used */
long ares__tvdiff(struct timeval t1, struct timeval t2);
#endif

#define ARES_SWAP_BYTE(a,b) \
  { unsigned char swapByte = *(a);  *(a) = *(b);  *(b) = swapByte; }

#define SOCK_STATE_CALLBACK(c, s, r, w)                                 \
  do {                                                                  \
    if ((c)->sock_state_cb)                                             \
      (c)->sock_state_cb((c)->sock_state_cb_data, (s), (r), (w));       \
  } WHILE_FALSE

#ifdef CURLDEBUG
/* This is low-level hard-hacking memory leak tracking and similar. Using the
   libcurl lowlevel code from within library is ugly and only works when
   c-ares is built and linked with a similarly curldebug-enabled libcurl,
   but we do this anyway for convenience. */
#define HEADER_CURL_SETUP_ONCE_H
#include "../lib/memdebug.h"
#endif

#endif /* __ARES_PRIVATE_H */
